XVIII. Contributions to the Anatomy of the Central Nervous System in Vertebrate 
Animals. 
By Alfred Sanders, M.R.C.S., F.L.S. 
Communicated by Dr. Gunther, F.R.S. 
Received December 11, 1885,—Read January 7, 1886. 
[Plates 38—41.] 
Part I.—Ichthyopsida. Section I. — Pisces. Subsection II. — Plagiostomata. 
Introduction. 
Among the numerous writers who have turned their attention to the nervous system 
of Fishes, a list of whom comprises most of the great anatomists of the present and 
past century, nearly all have confined their investigations to the brain of the Teleostei, 
to which their attention was almost exclusively directed, and only to a small extent 
was the nervous system of the Piagiostomata referred to. The names of these writers 
were given in the first of this series of papers. # Busch t was the first who devoted a 
treatise entirely to the nervous system of the Plagiostomata, with which he combined 
the Ganoids. Written in Latin, this is a plain and, upon the whole, accurate descrip¬ 
tion of the external or macroscopic appearance of the brain of the Plagiostomata and 
Ganoids. 
Miklucho-Maclay’s | contribution, also macroscopic, appeared in 1870 . In it he 
propounded an entirely new theory as to the arrangement of the various parts of the 
central nervous system. I have made some remarks on this in a former paper ; suffice 
it here to mention that he describes as the thalamencephalon (“ Zwischenhirn ”) that 
part of the brain which the majority of anatomists consider to be the optic lobe, and 
the lobe which almost unanimously has been described as the cerebellum he maintains 
to be the mesencephalon, while he restricts the term hind brain to the small posterior 
and inferior tuberosity of the cerebellum. 
* ‘ Phil. Trans.’ (vol. 169, pp. 769—772), 1878, part ii. 
t “ De Selachiorura et Ganoideorum Encephalo.” Berolini, 1848. 
t “ Beitrage zur vergleictiende Neurologic der Wirbelthiere.” Leipzig, 1870. 
